Saved from scrap

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
25,716
Reaction score
38,312
Location
Stockton, Ca.
Seems like the misfiring cylinders would cause the overheated converter? Or would the converter cause the cylinders to misfire? Let us know how this turns out.
backpressure test is what determines it ultimately, on mine it should have 2.5psi max but was reading 5psi at idle and 10psi when throttled up
 

TollKeeper

Full Access Member
Joined
Feb 21, 2010
Posts
2,990
Reaction score
5,901
Location
Brighton, CO
My last car that made the converters glow red, it was not the converters, but the ECM Driver was double pulsing the injectors, once when it was supposed to, and once 180* out, so it was dumping raw fuel into the exhaust.

Replaced the ECM, and that solved the problem... And increased my fuel mileage!
 
Last edited:
OP
OP
D

Dan2002

Member
Joined
Apr 27, 2017
Posts
55
Reaction score
28
nders would cause the overheated converter? Or would the converter cause the cylinders to misfire? Let us know how this turns-----------

well, after new converters , it is still giving me code p0300. o_O

any ideas whats the next step i should take?

new plugs and wires
new coils.
new fuel injectors
new cats
new all 02 sensors
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
11,610
Reaction score
23,564
Location
Elev 5,280
Did I miss what the short- and long-term fuel trims look like?
 
OP
OP
D

Dan2002

Member
Joined
Apr 27, 2017
Posts
55
Reaction score
28
Did you clear all codes after installing cats?
yes all codes cleared before starting the vehicle, then i started the vehicle and no lights were on but it wasnt running smooth, so when i attempted to acelerate the check engine light cames on flashing, and gives out code p0300 only code.
 

rockola1971

Full Access Member
Joined
Dec 29, 2016
Posts
2,569
Reaction score
3,412
Location
Indiana (formerly IL)
yes all codes cleared before starting the vehicle, then i started the vehicle and no lights were on but it wasnt running smooth, so when i attempted to acelerate the check engine light cames on flashing, and gives out code p0300 only code.
Flashing check engine light means active spark knock. You need to get a scanner on that top see which cylinder(s) are knocking. Could be bad knock sensors or their harness or a bunch of other things. Need to see if we can get it narrowed down to certain cylinders only or all cylinders.
 
OP
OP
D

Dan2002

Member
Joined
Apr 27, 2017
Posts
55
Reaction score
28
Flashing check engine light means active spark knock. You need to get a scanner on that top see which cylinder(s) are knocking. Could be bad knock sensors or their harness or a bunch of other things. Need to see if we can get it narrowed down to certain cylinders only or all cylinders.
yes, i have already seen with my scanner and live data.

i see number 7 cylinder misfiring the most
 

drdave81

Full Access Member
Joined
Oct 7, 2020
Posts
219
Reaction score
315
Location
Waterford, MI
Flashing check engine light means active spark knock. You need to get a scanner on that top see which cylinder(s) are knocking. Could be bad knock sensors or their harness or a bunch of other things. Need to see if we can get it narrowed down to certain cylinders only or all cylinders.
No a flashing check engine light means you have a catalyst damaging misfire. Basically you are sending raw fuel right into the cats. That's why the one was glowing. OP fixed a symptom, not a cause.
You need to figure out why you have no spark, or not adequate enough spark to properly light the air/fuel mixture in the cylinder.
 

rockola1971

Full Access Member
Joined
Dec 29, 2016
Posts
2,569
Reaction score
3,412
Location
Indiana (formerly IL)
yes, i have already seen with my scanner and live data.

i see number 7 cylinder misfiring the most
How much of a difference between #7 and others that are showing misfires? You may have narrowed it down to #7 and that would be a big help in figuring out what is going on. First I would suspect the wire. Swap with another and see if the misfire moves too. Then if that doesnt change anything, put it all back original and swap coils and see if that moves the problem to another cylinder. If no change after wire and coil change then you are down to the spark plug, coil wiring harness, output of PCM to fire coils and then the valvetrain and rings of the #7 cylinder. That would need a compression check to see where you are at there and at that time all 8 cylinders would need to be checked to see how #7 looks in comparison.
Ive chased my rear many times over a bad spark plug wire that visibly looks fine but in the dark you can usually see the lightning jump from them to ground depending on where the flaw in the wire is. So at night start it up and with hood raised have a look at #7 to see if you see a light show, also listen closely for a snapping sound. Keep your hands in your pockets so you dont get in the fan or find the lightning the hard way....with your hand. A coil with a cracked housing can do the same and the lightning will jump out to ground (metal) and it will make a snapping sound also. Ignition voltage is over 20kv so dont find out the hard way! Itll make you pee yourself!
 

Forum statistics

Threads
131,766
Posts
1,856,508
Members
96,041
Latest member
deniseholloman

Latest posts

Top